Vacuum regulation.



H. c. sNoo'K & E. W. KELLY.

VACUUM REGULATION.

APPLICATION FILED JULY 3, 19H.

Patented J ne 15, 1915.

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H. C. SNOOK & E. W. KELLY.

VACUUM REGULATION.

APPLICATION man JULY a. 1914.

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INVENTORS M L A-rroRNEY H. C. SNOOK & E. Wl KELLY. VACUUM REGULATION.

APPLICATION FILED JuLv s, 1914.

1,143,327. Patented June 15, 1915.`

s SHEETS-SHEET 3.

Flai@ P c N sa A v @Z-rons 59M- mm M24-65.@

H. C. SNOOK & E. W. KELLY.

VACUUM REGULATION.

n APPLICATION FILED JULY 3, 1914.

1,143,327. Patel-ned June 15, 1915.

5 SHEETS-SHEET 4- WITNESSES W ATTORNEY H. C. SNOOK & E. W. KELLY.

VACUUM REGULATION.

APPLICATION FILED IuLYS. 1914.A

1 ,143,327, v Patented June 15, 1915.

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y or high tension sides of the source of current supply.

" j of part of Fig. 5. Fig. 7 is a diagrammatic view of a further modification of a part oit'v A UNITED PATENT onriou.

l Houma.. cLYDE k-sNo'oiz, vlerevNwirn", EDWIN w. KELLY, or PHILADELPHIA,

PENNSYLVANIA. i vvaccini: nEGULfATroN.

Tara 'whom t ma!! Concern: y

' Be itknowii thatwe,"HoMER CLYnE SNooK I and EDWIN lV. Kmimnfcitizens of the United States, oilv Cynw'yd and Philadelphia, State of Pennsylvania, `have invented new and use- `ful Improvements in" Vacuum Regulation,

of vwhich the following is a specification.

vv'By our invention we make use of the principle of osmosis for the'introduction of 1 l gas into or removal of gas from the vacuum,

though as to some features ofour invention vacuum regulators operating on ,other principles may be employed.

rIn accordance with our invention gas may be introduced into the vacuum to lower the vacuum, or removed from the vacuum to raise the vacuum, at will; or a current of gas, of either constant oi varying quantity, may be continuously or intermittently i passed through the vacuum tube.` `And in `accordance vwith, our invention the vacuum lowering regulator and the vacuum raising y regulator may be operated differentially, by

vas,V

either manual or automatic control, and in response to electrical conditions, reiiecting vacuum conditions, of either thc loWtension Our invention resides in the .features hereinafter described.

forms' our invention may take reference is to be had to the accompanying drawings, in

which:

Figure 1 is a longitudinal sectional View through an X-ray tube and its regulators. Fig. 2 is a horizontal sectional view taken through the regulators of Fig. 1. Fig. 3 is a diagrammatic vView illustrating a mode of manually controlling the vacuum regulation. Fig. 4 is a diagrammatic view illustrating av modified form. of manual control for the regulation. Fig. 5 is a diagrammaticy vieiv ofregiilation by manual control in the low tension side of the circuit. Fig.

6 is a diagrammatic view of a modification Fig. 5. Fig. 8 is a diagrammatic view of automatic regulation by use of loW tension current. Fig. 9 is a diagrammatic view of speciacatioii af Letters Patent. ,reputation nieapiuiy a, i914. serial No. 848,708.

potentials. Fig. 10

v our regulator may-take.

For an illustration of some of the manyv Patented June'15, 1915.

automatic .regulation in response to high illustrates a, mode of automaticl 'differential regulationl in response tol high potentials. Fig. 11illustrates a mode (if-regulation responsive to highk potentials. Fig. 12 is a sectional view of `a form Fig. 13 is a sectional view'of another form: our regulator maytake.y

In., Fig. 1 is illustrated an X-ray tube fitted with regulators and with means for cooling the v*X-ray tube andits cathode and anti-cathode. A tube` so. cooled by air or lother suitable medium coperates advantageously with v,our system of j regulation, though it is to be understood that our invention is equally applicablev to vacuum tubes or X-ray tubes which are not cooled or which may be of any other type.

Referringto thedrawing, B is the usual glass bulb of an X-ray tube having the usual 'glass anode stem D and the usual glass cathode stem E. Within the tube are the usual anodeor target A and cathode C. In

the example illustrated the head 1, of copper or other suitable material is secured to metallic tube 2, as of steel, which lits over the,

vtubularglass stem 3 joined to the stem D at 4.. A tube v5, of copper or other suitable material, is set into the head l and preferably Welded theretov forming a. vacuum tight joint. The tube extends through the stein D and at its end is Welded or soldered at a vacuiimtight joint to the lplatinum or other tube 6y Which is sealed into the end of the glass stem D forming a vacuum tight joint. A corrugation 6a in the tube 6 yields, under` expansion and contraction of the tubel 5- due to temperature changes, and thereby prevents breakage of seal between tube 6 and glass stem D. Within the tube 5 is disposed a metallic tube 7 which at its inner end has any suitable metallic projection 8 forming Lelectrical contact With the tube 5 or head 1.

Near its outer end the tube 7 yis connected, as

' by soldering or braziii'g, vto the metal feriule 9 embracing the endfof the glass stem D.

' Electrical connection is made from the positiveV terminal of a suitable high tension source of current With theerrule 9 or the tube 7. The extreme end of the tube 7 is connected by rubber hose or otherwise with a supply of any suitable cooling medium,

for example, a supply of air under pressure.

Accordingly the air Will pass into and through the tube 7, strike the head 1, from which the tube 7 is suitably spaced, extracting heat from the head1 which conducts the heat away from the target proper, the air then passing outwardly as indicated by the arrow through the annular space between the tubes and 7 to the outer air through perforations 10 in the cap or ferrule 9.

The cathode C is counterbored to receive the tube 11 of copper or other suitable material, there being a vacuum tight joint between the cathode C and the tube 11 as by welding, brazing, soldering, etc. At its other end the tube 11 is welded, soldered or brazed to the latinum tube 12 sealed in the outer end of tlie glass cathode stem E making vacuum tight joints. Within the tube 11 is a metallic tube 13, spaced at its inner end from the cathode C and having the projection 14 making electrical connection wlth the cathode C or the tube 11. The other end of the tube 13 is soldered or otherwise connected to the metallic ferrule 14, making an air tight joint therewith, the ferrule 14 being secured upon the end of the outer tube or sleeve 15 of glass or any other suitable material. Electrical connection is made from the negative terminal of the aforementioned source of current with the ferrule 14 or the tube 13 which communicates electrically with the cathode C. The sleeve or tube 15 is supported upon the glass cathode stem E by the member 16, of cork or other suitable material, which has a plurality. of longitudinally extending grooves 17 formlng air passages. The tube or sleeve 15 preferably terminates in the bell 18 which extends around the bulb B to any suitable distance.

Air or other cooling medium is introduced into the tube 13, passes therethrough and strikes the cathode C, cooling the same, and then passes outwardly in the annular space between tubes 11 and 13 into the sleeve or tube 15 thence through the passa es 17 over the outside of the cathode stem into the bell.18 from which it issues over the' outer surface of the bulb B, all as indicated by the arrows. And we have found t at the air or other medium issuing from the l 18 clings or remains close to the bulb B even beyond its middle or equator.

Sealed to the bulb B is a tube 19 whose interior space 20 is in communication with the .interior of the bulb B. Supported by the tube 19 is the glass bulb or vessel 21 into which projects the tube 22 of platinum, palladium or any other suitable metal or material which is capable of operation as an osmotic member or membrane. The free end of the tube 22 is closed and its otherend is sealed in the glass and its open end communicates with the space 20. An electrical connection is made by conductor 23 from the tube 22 to the platinum or other wire 24 sealed through the wall of the bulb 21. A

isecond platinum or other suitable Wire 25 is sealed through the Wall of the bulb 21 and is referably provided at its inner end with a utton or head 26 of copper or other suitable material, preferably tip ed with platinum, the head or button 26 belng spaced from the tube 22 to form a spark gap, that part of the tube 22 directly opposite the button 26 being preferably thickened or provided with a layer of metal, such as a coil of wire 27, preferably of platinum, to prevent burning the tube 22. In the "essel 21 is confined a mass of gas or gasesv which are to be introduced into the bulb B for lowering the -The gas in the bulb 21 is preferably hydrogen, though it is to be understood that any other suitable gas or mixture of gases may be employed. For example the monatomic gases such as argon, helium, neon, zenon, etc., may be employed either singly, or in combination with hydrogen or other gas.

A second tube 28, provided with a coil 27', 1s sealed in the glass and has its open end in communication with the space 20 while its outer closed end is within the tube or bulb 29, in this case shown open to the atmosphere at 30. An electrical connection from the tube 28 is made'by conductor 31 to the platinum or other wire 32 sealed in through the wall of the bulb 29. And disposed opposite the tube 28 is the button or head 26 in electrical communication with the platinum or other wire 33 sealed through the wall of the bulb 29.

While the bulb 29 is shown open to the atmosphere, it is to be understood that the same may be closed to the atmosphere, like bulb 21, and may be more or less evacuated, or may contain gas other than any of the gases admitted to the bulb B through tube 22. And when the bulb 29 is open to the atmosphere as shown, the gas or gases admitted to the bulb -B through tube 22 should be other than the nitrogen or oxygen of air or any other gas present in the air in substantial concentration. When it is desired to lower the vacuum within the bulb B a current of suiiciently high tension is passed across the gap between the head or button 26 and the tube 22 to heat the same t0 suficiently high temperature, as, f or example, above red heat.

We have found that by making the tube 22 the cathodeand the button 26 the anode of the spark gap the heating `is most advent:igeously-A actuirnplished',l

particularly l when "the .pressure `of the gas .1n-the. spajr gap is-very muclghi her than that within fthe vtuilbB. The' wa of the tube 22 jbein'g- 'now heated',- hydrogen, for example, will` I passl'by osmosis from the bu1b21 throu vh the membrane wall/of the tube 22` to t f vdeed as compared with' the pressure within the :bulb 21. .If on the'other handit is de- 'sired to raise the vacuum, that is, take hy' drogen or other gas out of the bulb B, current is' passed across the gap between the button or head 26 and the tube 28, the la-tter again being the cathode by preference, and when the tube 28 is heated, and there being substantially no hydrogen in the air or within the tube 29, hydrogen will come out of the bulb B by osmotic action through the tube 28 and through its wall into 'the bulb 29, notwithstandingthe fact that the gas pressure in the bulb 29 is very many# times higher than the gas pressure withinl the bulb B. VBy preference, particularly when hydrogen is in the bulb 21, we make the tube 22 of Aplatinum and the tube 28 of palladium. That is,`in the lowering regu lator we prefer to use a. material for the tube 22 through which 4the gas does not so readily pass by osmotic action, while the tube 28 is preferably made of avmaterial through which the gas vwill very f readilyr pass by osmotic action. Temperatures, thicknesses of walls or osmotic membranes and differences in concentration of gas'with-v in and without the osmotic membranes being the same, the tube 22 may be said to have a lower osmotic co-eilicient than the tube 28. Palladium has so high an osmotic co-elicient ythat we prefer not to use it in the lowering regulator, though it is to be understood that it may be there used'. And this' property makes `it particularly desirable for the raising regulator as described.

tors.

In electrical Vcommunication with the wires 25 and 33l may be provided the conductors 34 and 35 spaced from each-other'to form a spark gap. f y

ln Fig. 3 is illustrated a'mode of connection of the X-ray Ltube and the regula- Here the positive conductor from the source of high tensionl current or operating the X-rayftube is connected tothe switch arm 36 normally engaging withrthe contact 37 connected by conductor' 38,'.with the anode of the X-ray tube B. N is the negative conductor of the high tension source, and is connected to the switch arm 39 normally in engagement-...with the contact 40 connected by conductor 41with the cathode of the X-ray tube. Either of the switch arms 36er 39 may be swungover 'into en- -Lmasafvl y y gagement vwith-icontact 'l "in" 'the cords 43 or. wrappedaroundfplll ,i2-y' 45 and46 attached respectively.tdlthegswitcli )arms 39 or 36. Howeverfswitcharm@36:1o the presentrpurposes may remainiii-*contact is pulled, transferring the-switch arm 39'd to' hooked on to wire 24 'and then7 the eo'rd: v43 l contact 42, whereupon.. current will 'pass from the positive conductor P through switch arm 36, conductor 38 and conductor 'f y r48 connected with wire 35, then leaping the gap between wlres 35, and 34 will vpass through wire 3,4 and button`26'acrossl the e gap 'to' tube 22, thence -through conductor 23 and wire 24'and'con'ductor 47 and switch blade 39. to the negative conductor N.- The osmtic tube 22 will accordingly be heated .and gas will pass into the `bulb B to` lowerr the vacuum. If on the other hand it is desired to raise the, vacuum, instead of connecting the wire 47 to ywire 24 it will be connected to wire 32. Since it may be more often-required to lower the vacuum, the wire 47 may be left normallyin connection with y wire 24. Andv if the wire 47 is ofgzconsiderable length it .has substantial electrostatic capacity, and forthis reason the` gap' beal tween the conductors 35 and 34 is 1o( provided to prevent charging the wire 47 while the X-ray tubeis in operation, the displacement l current otherwise resulting would` cause ythe lowering regulator to operate slightly and so undesirably lower the vacuum.' y l' InFig. 4'th`e arrangement is similar to that in Fig.` 3 except that tothe conta`ct`42 is pivoted a switch arm-49normally retracted by spring 50 into engagement with contact 5l connected by conductor 47a to wire 24. With the parts in this position, to 'lower the vacuum, it is simply necessary to "swing the switch army-39 over on to contact 42'. Ifv

itis desired to raise the vacuum,"the cord 52 is Pulled, moving the switch 'arm49 in'y f oppositionto spring 50 into engagement with contact 53 connected by conductor 47b the reversing switch S and adjustable resist-4 ance R to the primary 20 of the transformer Tv having the highv potential vsecondary sdelivering current through the synchronous high potential rectifying. switch l'F tol 'the positive and negative. high tensionl kconduc- 1 Ytors and N connected .respectively to theV with contactf37'.v x In .Communicationfwith y? contactl42 1s the conductorf47 .which "may`f.. Xbe 'connected to veither" thewire' 24.v of thel the resistance r1. and r2 adapted to be swept over o r enga ed by themanually lor otherwise operate switch arm 55 connected lto the otherconduetor 56 of the low tension alternating currentcircuit.` 'Associated wlth i the primaries p1 and p2 areithe secondaries I' is a secondary of a transformer whose pri-- s1 and s2, in whose respective circuits are included thel lowerin and raising osmotic tubes 22l and 28. Slnce these tubes 22 and 28 communicate with the' interior of the X- ra tube, during operation of the X-ray tube these regulator tubes assume high potentials, and consequently between the prlmaries ,p1 and p2 and their secondarlesl 81 and s2 is provided high potential insulation 57.- By this arrangement the X-ray tube may be kept in operation by energy delivered by the high tension conductors P and N and while in operation the vacuum may be lowered by brlnging the switch arm 55 into engagement with resistance r1, whereupon the secondary s, will pass current through the tube 22, the resistance of the tube 22 and the current strength being such 'that the tube 22 is raised in temperature,

the temperature increasing as the amount of resistance r1 in the circuit is decreased. And similarly if it is desired to raise the vacuum the switch arm 55 is brought into engagement with resistance r2 whereupon the tube 28 is similarly heated by current derived from the secondary s2.

Instead of connecting the tubes 22 and 28 in the manner shown in Fig, 5, they may be connected in the manner shown in Fig. 6 with relation to the secondaries s,L and s2. In this case these secondaries deliver current at potential high enough to leap the gaps of the characters ldescribed in connection with, Fig. 1. Or as illustrated in Fig. 7, s,

mary is in the low tension alternating current circuit of Fig. 5. I-Iere one terminal of the secondary s3 is connected to the interconnected tubes 22 and 28, a variableconnection 58 being made with'the resistance 'r3 both of whose terminals are connected to the other terminal of the secondary s3. By this arrangement heating current is passed through both vtubes 22 and 28 so that both are continuously respectively admitting and extracting gas from the bulb B. By shifting the connection 58v along the resistance r3 one tube or the othermay be heated at will to higher temperature than the other and thus secure a diierential regulation in that gas may .be admittedmore rapidly than it 1s extracted or extracted more rapidly than it is admitted. A nd whatever the position of the variable connection 58 there will be in eiect a continuous stream of gas owing into and out of the X-ray tube, unless, indeed, the temperatures of thc tubes 22 and 28 are too low. A similar diilerential action may be secured by the arrangements .shown in Fi s. 5 and 6 by simply connecting the free en s of the resistances r1 and r2. A nd Fig. 7 may be modified in accordance with Fig. 6 so that diiierential regulation is available when the spark gaps are used for passing current to the tubes 22 and 28.

In Fig. 8 the source of alternatingcurrent and high potential rectifying switch of' Flg.- 5 arev omitted, it being understood that the secondary g delivers high potential alternating current through the rectifying switch 4throu h the high potential conductors P and I-Iere there is connected in p arallel with the plrimary p of the high tension transformer the winding of an electro-magnet l59 whose armature 60 is carr 1ed by the'lever 61 pivoted at 62. Connection from conductor 56 of the low tension alternating current circuit is made with the lever lcarryin the contact 63 adapted to engage either o the stationary contacts 64 or 65 adjustable laterally by the adjusting screws 66 and 67 respectively. The contacts 64 and v65 are connected respectively with one terminal of each of the primaries p1 and p2 whose other terminals connect with the conductor 54 of the low tension alternating current circuit. Attached to the lever 61 through spring 68 is the member 69 carrylng pointer 70 coperating with the scale 71. The pointer 70 may be moved to any point on the scale 71 and then clamped in the adjusted position. When the transformer T has suhciently low magnetic leakage, the potential difference between the terminals of the primary p will rise and fall with the vacuum in the X-ray tube, since with higher vacuum the potential across the anode and cathode of the X-ray tube is high,

and with lower vacuum the potential across the anode and cathode is lower while the tube is in operation. In `consequence when the vacuum in the tube becomes higher the potential across the terminals of the primary p will become higher with resultant greater current through the winding of electro-magnet 59 which accordingly more powerfully attracts its armature 60, thereby bringing contact 63 into engagement with contact 64 energizing primary p1 and causing its secondary s1 to deliver current either conductively through 'the tube 22 as shown in fFig. 5 or across a spark gap as shownin Fig. 8 and Fig. 6. In .any event when the primary p1 is energized the osmotic tube 22 of the lowering regulator is heated and the vacuum in consequence automatically lowered. If on the other hand the vacuum should become lower, the potential acrossthe primary'awill felt-and the" 11m-magnet 59. will Y lbe weal'ieaeiij andfltls '.1

I Whether or not the high tension transformerv spring 6 8 will then gain control-of theleyer ffygl 61 bringing contact 63 into engagemcntwith n contact 6 5 therebcausing current heat theraisingregulator tube 28,.;to cause an automatic raising of the 'vacuum. By setting. the pointer 70 to an desired point. in

scale 71, which may be ca 'brated in degrees of. hardness of'the X-ray tube, or in lengths of parallel sparkgap corresponding with X- ray tube resistances, vautomatic, 'regulation l may-be pbtained for the desired` degree of vacuum in the tube. And the apparatus willv then o erate automatically to keep the vacu-v the X-ray. tube substantially that 84 and the spuug' Z6. mam@ L balanced. asshown- 1.5 Iff-hQWQFe corresponding with-'the scale indication. The margin lof uctuation to either side of.

this value will b e made smaller by adjusting the screws 66 and 67 inwardly so as to' brlng contacts 64 and 65 nearer 'thecontact 63. Or by adjusting these screws outwardly, and separating the contacts 64 and 65 from contact 63, the margin of fluctuation `of vacuum to either side of .that indicated by lthe scale will be increased.

- In Fig. 9 the automatic regulation is procured in response to fluctuations inl potential of the high tension circuit across the anode and cathode of theX-ray tube. This method of regulation is therefore available T has small magnetic leakage. The high 4tension positive and negative conductors P and N connect with the anode and cathode respectively as described. However, in one vof theseconductors, as P, ythere is a spark gap 4between the stationary terminal 72 and the adjustable terminal 73, the energy passed through the X-ray tube passing over the gap between these terminals. In this case the current for heating the regulator v tubes 22 and 28 passes over the spark gaps vsimilar' to those described inconnection with Fig. v1. Connection for this purpose is made from positive conductor P tothe conducting member 74 pivoted at 7 5 and controlled by the torsion spring 76 whose free end carries a pointer, 77 which may be clamped in any desired position with respect to the scale71j similar tothe scale 71 in Fig. 8.y The-member 7 4 carries the adjustable contacts `7 8 and 79 coperating respectively with the spark gap terminals 26 and 26 and normally separatedg therefrom by spark gaps. To the insu lating member 80, attached to thebeam or .member 74, *isl attached the metallic are-81 disposed oppositely Ato the stationary' metallic arc, 82 vwhich latter is connected with ithe negative conductor N. The arcs 8 1 and-82 mav be electrically connected to eachother by uthe small easily iiexible wire 83. On the opposite end of the beam 74 isv an aditistable counterweight 84 for ,balancing the beam so energizing primgnyhpz: um Ithe'secondary 82 to v lengths of the:

will .pass thnoughthe re 'gap length )is- 1.161

e1. and, 'sawing diametre@ is shorter than the spark gap betweenthel n.95

later spark :gaps

lterminals 7 2 and y7 3 whereupon the current at the right heating .the Ow'erins regulator scloser to. the vccnductor 26 so that.ievexitually tube22'causing the vacuumtobe-automatig cally loweredif the vs aicuum-A has raised-te a great lextent vthe unbalancing fof vthe beam .74 will be so great as to 'bring Contact 78 inta engagement with contact '-26 1:, which latter ,then acts as .astop for the beam.

i On the other hand if thevacuumof the tube is tno low it willbe automaticallvrasedbecause-of the decrease of potentialof the armsl and 82e11ewing the beam T4-.t0 move in a counterclockwise .direction onf; its Pivot 7 5.- to. shorten the Ygap atjthe .2 6- thereby eausingzthe Vcurrerlt- :tnass' across the spank gap .between 7 9 angliae.

te heat .the raising reglatortubeg calieing .the antemano raising of the Macu-um.'

By adj listing Vthe. screw' contacts 7?, 78:. and.

79 the arnountotgvariationof -vacuiilnlto .either vside? of that 'indieated abv the-s ale Hamer-be adjusted?. if the connecti'xi 83 'between the arcs f 81 zand-82 isomittdand when-in .suchcase the arc .81 remains .as dicated the drawing or is-connect'edto: the

positire vconductor P, inf latte'rcase .Substantial i inslation .intervening .between arcs @l and 82,-tbearcs'81 and-82 willrcarry. fhefgfs f QpPQsite signs and wlltherefore e 'attractfeachothen this {attractive force will varywiththe potential dlce. across the' X-rey tubs. terminale a d there fore with the degree offini'eiiiiin. .ith :fall:L ing vacuum the attractionjbetwn ar 81 and 82 will vla;esti-1e .les and, the-bni# 74s 2W iii ' rated by a small spark gap 'will then move in a clockwise direction about its pivot 75. Accordingly for this arrangement the arcs 81 and 82 and the counterweight 84 should be interchanged as to their positions with respect to the beam 74, or the spark gaps for the regulator tubes should be interchanged.

In Fig. lO is illustrated a mode of automatic differential regulation responding to variations in potential conditions between the terminals of the X-ray tube, the same being operative while the X-ray tubo is in operation. In this case an electrostatic instrument, which may be of the character illustrated or which may be of the quadrant electrometer type, responds to variations of otential to control the .vacuum regulators.

ere thel two spark gaps of the regulators' 'are' in series with each otherbetween the ositive conductor P and the anode A of the -ray tube.' 4In shuntv to these two spark gaps inseries is the-high resistance rr sepafrom the terminal 85 on the conductin member 86 pivoted` atv 87 and controlle by the torsion spring 88l at whose end is carried the pointer 89 co erating with the scale 71", similar to scales 1 vand 71 of Figs. 8 and 9, the pointer `89 being Vmovable to any point along the,

scale and there clamped.. The member 86 carries the arc shaped conducting plate 90 coperating with the stationary arc shaped 'conducting plate 91 connected to lthe negative conductorN. Suitable high tension insulation 57 intervenes between members 90 and 91 to prevent sparking across them.

' he plates 90 and 91 become oppositely charged at high potential and their difference in potential fluctuates with the vacuum in the X-ray tube. As the vacuum in the X-ray tube raises, the potential dilI'erence between the plates `9,0 and 91 increases and the attractive force between them increases with the result that the member 86 lrotates in a counterclockwise direction on its pivot 87 withl the result that that part of resistance 'r4 in shunt with the spark gap between tube 28 and the button 26v of the raising regulator is decreased so that this regulator` spark gap will be more or less completely robbed of its current and therefore the tube28 will cool; simultaneously more current-will pass from positive conductor P through resistance r4 to the terminal 85 and thence to button 26 and across the gap to the lowering regulator tube 22,

with the result that the tube 22 will increase" moves in clockwise direction with relative -decrease in temperature of tube 22 and increase of temperature of tube 28.

employing high tension potential differences is illustrated. Here the terminal 85 on the member 86 `pivoted` at 87 and having the control spring 88* is separated by a substantial spark gap from the arc shaped contact 92 connected to both of the regulator tubes 22 and 28;' With the terminal 85 which may serve also as a pointer is associated a scale 71c similar to the scale 71b of Fig. 10. The length of spark gap between members 85 and 92 is greater than that of each of the regulator spark gaps.`

positive conductor P connects with the member 86. When the vacuum of the X-ray tube raises the potential difference between the plates 90 and 91 increases with the-result that the member 86 parta-kes of clockwise movement about its pivot 87, current in the meantime passing from positive conductor P across the ga between members 85 and` 92 and thence directly to the anode A, and

Vthence through the X-ray tube to conductor N. When the potential rises suliciently the contact 85 approaches or engagesthe contact 93 whereupon current will pass across lthe gap at the regulator tube 22 increasing the temperature of the regulator tube 22. Fall of vacuum of the X-ray tube is accompanied by movement of the member 86 in l,opposite directiomand when it closely approaches or engages the contact 94 the regulator tube 28 is similarly heated with resultant raising of the vacuum. The contacts 93 and 94 may be placed at any desired positions along the scale 71; and as the contacts 93 and 94 are placed nearer and nearer together the margin of regulationis progressively decreased.

In Fig. 12 is shown a form of regulator which may be used both for raising and lowering'the vacuum of the main' bulb or X-ray tube and in which the gas to be introduced into the tube is liberated or produced as and when required. Here the osmotic tubeI 22 consists of palladium, though other suitable material may be employed. In the bell or bulb 29* open to the air at 29b,'is a cork or other member a through which extends the glass or other tube b in whose outer end is a cork'or other stopper member c through which extends the wire or conductor cl terminating in the space e between the part c and the wall f of porceeol lain'orother crousmateriaal hvirhich` extends the p fatinu'm'zol? Qthergconnuctor g,

' the member`295l A' wire 2 5 may be lsealed the,ftube 22* extending7`into the mouth-of:- the bottle or tube. 'bj and."separated by 'ai gap from the conductor g. ."'The tube .22 isc011 nected by conductor 23'.to`the Wire '24* tha-@bear `.desi'redl' to @lower the vacuum, 0f, the main bulb "or X-ray .tube current lis the ositive conductor d throu .prfe ectr'olyt'e inthe yspace c to t econductor g `and lthence across the gap to the .tube .22*` which yis again preferably a cathode. -Elhe passageof the electric energy through the vmaterial in the space'e causes by velectrolysis the evolution of hydrogen, which passes through the porous member f into the space surrounding the end of the tube 22, and since `such tube is heated by passage .of the current .the gasv will pass through the; osmotic wall of the tube 22a into the space 20 communicating with the interior of the main bulb or X-rayftube, to lower the vacuum. Or when oil or other hydrocarbon is in the space e, the wires d and g may be connected together, inwhich .case some of the oil or other material will be carried through member fby electrostatic action,

and then decomposed into hydrogen or other as vwhich then passes through the/heated ivall of the tube 22 .into the main 'bulb or X-ray tube to lower the vacuum. The same -tube 22amaybe usedv for raising the vacuum, by connecting the wire 25% with the posltive conductor of the circuit and causing the current to leap the gap tothe cathode 22L heating the same, whereupon hydrogen' or other gas'will pass into the main bulb or Xfray tube through the wall of the tube material. The member h may be hollowed out oil vorv hydrocarbon or other suitable maat'its innerend vas shown to receivethe end vof the tube 229. And the positive conductor may be connected to the member h in any suitable way as by wrapping .the same around the member* h several times. The pores of the member k are .charged with an 'terial as described in connection with Fig. 12. On passage vof current from the conductor'iv .to the tube 22a which is connected vto the negative side of the circuit by *wireJ across thegap to the tube 22, whichjis surassedirom the Water. l

' bulbforf tube it is to be understood that other the ollow endof the member h around the .end of tube 22 which is heated by the spark por jarcwith the result that the .gas'will pass .through thefwallsiof the tube 2 2a into the Ispace in communication .with the main lbulbfor X- ra-y tube, v.thus lowering I'the vacuum. And the vacuumv may also be'v raised .by-.passing current from the wire a rounded by air, with .resultant raising` of the vacuumas hereinbefore described.

both automa-tic and manual-regulation.

While ywe have shown. anv osmotic regulai .tor for lowering the vacuum ofthe main types .of'regulator may be employed for this purpose and -coperate in the differential -and other regulations,"both automatic and manual, hereinbeforedescribed. For eX- ample, any other type of lowering regulator may -be used, such as those involving materlal 1n communlcatlon with the interior Y of themain tube or'bulb and which may be caused to yliberate gas-when heated or other- W-ise actedupon. In such case, however, it vis preferred that the gas liberated from such regulgator -shall be of such character as may,

And the losmotic members hereinbefore described may take other than tubular forms, any form of osmotic membrane being comllt will be understood thatthe'structure v.of either Fig. 12er Fig. 13 may be used in place ofthe two regulators inganyfof the .beremoved from the main bulb or tube by a I.raising Vregulator ofthe character described.

prehended within our invention, except v-where expressly ,otherwise stated.

Air cooling of the X-ray-tube is `of gen- .eral advantage in connection with an X-ray .or vacuum tube, but is of particular advan tage in connection with a raising regulator of the character herein described because by the air cooling, particularly of the glass wall in the vicinity 0facathode, prevents heating which is otherwise likely to occur at this region with resultant devitrication of the glass with resultant liberation into the vacuum of gases of a character which may not pass through the raising regulatormembrane.

What We claim is:

1. The method of regulating the vacuum of a vacuum tube, which consists in simultaneouslyintroducing gas into and extracting gas from the vacuum.

2. The `method of regulatingthe vacuum of a vacuum tube, which consists in simultaneously. introducing gas into and extract'- ing gas from the vacuum atdiii'erent rates.

3. The method of lowering `the vacuum of a vacuum tube, which consists in extractlng gas from the vacuum,y and Simultanef ously mtroducmg gas into' the vacuum. ata

eater rate than gas is extracted thererom. l

4. The method of raising the vacuum of a vacuum tube,4 which consists in introducing gas into the vacuum, and simultaneously extracting gas from the vacuum at a greater l rate than gas is introduced into the vacuum.

5. The method of operating a vacuum tube, whichconsists in impressln electrical energy thereon, and during the lmpression of energy thereon introducing gas into and extracting gas from the Vacuum.

6. The method of ,operating a vacuum tube, which consists in impressing electrical energy thereon, and during impression of energy thereon introducing gas into and extracting gas from the vacuum at different rates.

7. The method of operating a vacuum tube, which consists in impresslng electrical energy thereon, and during impression of energy thereon introducing gas into the vacuum and extracting gas from the vacuum at a lower rate.

8. The method of operating a vacuum tube, which consists in impressing electrical energy thereon, and during impression of energy thereon introducing gas into the vacuum and extracting gas from the vacuum at a higher rate.

9. The method of operating a Vacuum tube, Which consists in simultaneously introducing gas into and extracting gas from the vacuum, and automatically controlling the rates of introduction into and extraction of gas from the Vacuum. v

10. The method of"operating a vacuum tube, which consists in simultaneously introi ducing gas into and extracting gas from the vacuum,` and automatically controlling, the rates of introduction into and extraction of gas from the vacuum in response to a change in the degree of the vacuum.

11. The method of operating a vacuum tube, which consists in simultaneously introducing gas into and extracting gasfrom the Vacuum, and automatically controlling the rates of introduction into and extraction of gas from the Vacuum, and simultaneously impressing energy on the vacuum tube.

12. The, method of operating a vacuum tube, which consists in impressing electrical energy thereon, simultaneously introducing gas into and extracting gas from the vacuum, and automatically controlling the rates of introduction and extraction of gas in response to variations in difference ofpotentialbetween the vacuum tube terminals.

13. A regulator for the vacuum of a vacuum tube comprising an osmotic membrane, and a terminal external to the vacuum separated from said membrane by a spark gap.

14. A regulator for the vacuum of a vacuum tube comprising an osmotic membrane and a terminal external to the vacuum separated from said membrane by a spark 'gap said membrane constituting the Icathode of said gap.

15. A regulator for the vacuum of a vacuumv tube comprising an osmotic membrane, a bulb closed to the atmosphere andcharged with kgzs, said membrane separating said gas from the interior of said tube, and a spark gap terminal separated in said `gas from said membrane. I

16. A'regulator for the vacuum of a vacuum tube comprising an osmotic membrane, a bulb closed to the atmosphere and vcharged with an isolated mass of gas, said membrane separating said gas from the interior of said tu e, and means Within said gas for heating .said membrane.

17. A regulator for the vacuum of a Vacu- A um tube comprising an osmotic membrane, a bulb closed to the atmosphere and charged with an isolated mass of gas, said membrane separating said gas from the interior of said tube, and means Within said gas for electrically heating said membrane. v

18. A regulator for the Vacuum of a vvacuum tube comprising an osmotic membrane, y

a bulb closed tothe atmosphere and charged With gas, one side of said membrane exposed to said gas, and a terminal separated from said membrane Within said gas to form a spark gap.

19. regulator for the vacuum of a vacufum tube comprising an osmotic membrane, a bulb open to the atmosphere inclosing said membrane, and a terminal Within'said bulb spaced from said membrane to form a spark gap, said membrane constituting thev cathode of said spark gap. y

20. The combination with a vacuum tube, of a'bulb integral therewith and open to the atmosphere, an osmoticmembrane forming a wall between'the interior of said vacuum tube and the interior of said bulb and housed Within said bulb, and means for elecrially heating said membrane Withinv said 21. A regulator for the vacuum of a vacuum tubecomprising an osmotic membrane, a bulb open to the atmosphere inclosng said membrane, and' a terminal Within said bulb spaced from said membrane to form a spark gaP- Y 22. An X-ray tube comprising a main bulb, a second bulb carried by said Xray tube and sealing a charge of regulating gas, 'an` osmotic membrane separating said main and second bulbs, and means Within said second bulb for heating said membrane. A

23. A n X-ray tube comprising a main bulb, a second bulb sealed thereon, a charge of elemental gas sealed Within saidsecond brane.

. separating said bulbs, and an electrical conbulb,two bulbs'integral therewith, one of said two bulbs closed to the atmosphere and containing a charge of regulating VgaS,-the

second of said'two bulbs open to the atmosl phere, and osmotic membranes intervening between said two bulbs and said main bulb.

" 25. The combination with an X-ray tube` having Va main bulb, of a second bulb integral `therewith, an osmostic membrane nection to said membrane, a terminal spaced 'from said vmembrane to forma spark gap, and an electrical connection through said second bulb to said terminal.

26. vThev combination with an X-ray tube having a main bulb, of a second bulb integral.' therewith, an osmostic membrane separating said bulbs, and anvelectrical connectionto sa-id membrane, a terminal 'spaced from said membrane to form a spark gap, an electrical connection through saidsecond' bulb to said terminal, and a spark gap between said terminal and a main terminal o said X-ray tube.

27. An X-ray tube comprising aA main bulb, two bulbs integral therewith, one of said twobulbs closed to the atmosphere and containing a charge of regulating gas, the second of said two bulbs open to the vatmosphere, osmotic membranes intervening between said two bulbs and said main bulb, spark gap terminals spaced from said membranes, and a spark gap between said spark gap terminals. 28. The combination with an X-ray tube having vacuum lowering and raising regulators, of electrical switching means for dissimultaneously electrically controlling said regulators.

29. The combination with an X-ray tube having vacuum lowering and raising regulators, of' a source of energy for operating said X-ray tube, a switch for electrically controlling either of said regulators, and a switch for disconnecting a terminal ofsaid X-ray tube from said sourceand connecting said first named switch to said source.

30. The combination. with an X-ray tube having vacuum lowering and raising regulators, of a source of low potential energy, means for'converting said low energy to energy of high potential for operating said X-ray tube, and means deriving low potential energy from said low potential source for controlling said regulators.

31.` The combination with an X-ray tube having vacuum lowering and raising regula-- tors, of a source of low potentialenergy, means for converting said low energy to energy of high potential for operating said X-ray tube, and means deriving low potential energy from said low potential source for controlling said regulators alternately.

r' l 24. X-raffltube comprising a main 532.7The*'cillin-lbfVinatieriv with V an tube having vacuum lowering andr'aising regula'- tors, of asourceo'f vlow potential v energy,v

means for converting saidfenergy to energy oft-"high potentlal for operating said X-ray tube, and means 4deriving low potentialen# ergy. from said low potential source/for controlling said regulators differentially.

33. The combination with an X-rayftube` y having vacuum lowering and raisingregulaf tors, of' af source-oflow potenti-al energy', means for converting sald energy. vtofenergy of high potential for operating said vrX-'rary trolling said regulators automatically.' v

34. The combination with anX-ra'y tube having vacuum lowering and raisingregulators, of a source of-low potential energy,-l means for convertlng said energy to energy "i of vhighpotential for operating said X-'ray' tube, and means-deriving low potential en "erg'y from said low potential source forcentrolling said regulators automatically inresponse to changes in difference' of potential .between the 'terminalsv 'of said X-ray tube;l

35. The combination with an X- ray tube having vacuum-lowering and raising regula..

tors, of a high potential circuit for impress-v ing energy upon said X-ray tube, and auto-l matic means responsive to changes in difference in potential between the terminals of said X-ray tube for controlling 'said regu-l lators. l l

36. The combination with' van X-ray'tube having vacuum lowering and raising regulators, of a high potential circui'tfor rimpressing energy upon said X-ray tube, and auto.- matic means responsive to changes in differof vacuum of said tube for raising the vacuum thereof.

38. The combination with an Xlray tube,

of means for cooling the same, and automaticV means for raising and lowering the vacuum thereof in response to change in degree of vacuum.

39. The combination with an X-ray tube comprising a bulb, anl anti-cathode and a ence in potential between the terminals of.`

cathode, of means for cooling the exterior A of said bulb in the vicinity of said cathode,

and automatic means responsive to change in v degree of vacuum of said tube vfor raising the vacuum within said bulb.

40. rIhe combination with an X-ray tube comprising a bulb, an anti-cathode and Aa cathode, of means for cooling the exterior of y said bulb inthe vicinity of said cathode, and automatic means responsive to change in degree of vacuum of said ltube for rais-' lowering the vacuumlwithm said in and bu b. 41. `A regulator for the vacuum of a vacuum tube comprising an osmotic membrane, and a terminal external to said tube separated from said membrane by a spark gap,

' said membrane constituting the cathode of said spark gap.

V42. A Vregulator for raising the -vacuum of a vacuum tube comprising an osmotic membrane forming a wall between the interior of said tube' and a region at higher pressure, and a terminal external to said tube separated from said membrane to form ay spark gap. v

43. Means for regulating the vacuum of a vacuum tube comprising a raising regulator and a lowering regulator, said lowering regulator comprising an osmotic membrane, and a terminal external to said tube separated from said membrane to form a spark gaP Y 44. Means for regulating the vacuum of a vacuum tubev comprisinga lowering regulator and a raising regulator, said raising regulator comprising an osmotic membrane, and a terminal separated from said membrane to Vform a spark gap.

45. An X-ray tube lcomprising a main bulb, asecond bulb of hydrogen gas sealed within said second bulb, an osmotic membrane forming a wall between said gas andthe interior of saidv main bulb, and means for heating said membrane. k

46. Means for regulating the vacuum of a vacuum tube comprising a plurality of regulators, each ofvsaid regulators comprising an osmotic membrane, said membranes formed of different materials, and means for heating said membranes. 47. Means for regulating the vacuum of a vacuum tube comprising raising and lowering regulators, said regulators comprising osmotic membranes of different materials.

48. Means for regulating the .vacuum of a vacuum tube comprising raising and lowering regulators, said regulators comprising osmotic membranes of different materials allowing passage of gas therethrough at different rates under like conditions.

. 49. Means for regulating the vacuum of a vacuum tube comprising lowering and raising regulators comprising osmotic membranes, means for supplying gas to the outer side of the lowering regulator membrane, said membranes allowing 4 passage of gas tiherethrough with different degrees of freeom. v

50. Means for regulating the vacuum of a vacuum tube comprising lowering and raising regulators comprising osmoticv memb ranes, means for supplying gas to the outer s1de of the lowering regulator membrane,

vbranes ofv platinum and palladium,

sealed thereon, a charge Y tube,

lowing passage of said ga`s therethrough with-less freedom than the membrane of said raising regulator. l

5l. Means for regulating the vacuum of a vacuum tube comprising lowering` and raising regulators comprising osmotic membranes, means for supplying gas to the outer side of the lowering regulator membrane, said membranes allowing passage of gas therethrough with different degrees of freedom, said membranes being of different materials. A

52. Meansfor regulating ythe vacuum of a vacuum tube comprising lowering and raising regulators comprising osmotic membranes, means for supplying gas to the outer side of the lowering regulator membrane, the membrane of said lowering regulator allowing passage of said lgas therethrough with less freedom than the membrane of said raising regulator, said` membranes being of different materials.

53. Means for regulating the vacuum of a vacuum tube comprising lowering and raising regulators comprising osmotic mem- .respectively.

54. Means for regulating the vacuum of a vacuum tube comprising lowering and raising .regulators comprising osmotic membranes of platinum and palladium, respectively, the outer face of said platinum membrane.

55. The method of operating. a sealed vacuum tube, which consists in impressing electrical energy thereon, and dur-ing impression of energy thereon extracting gas therefrom automatically in response to change in degree of Vacuum.

56. The method of operating a vaccum tube, which consists in impressing electrical 'energy thereon, and during impression of in response vto change in difference of potential between the tube terminals.

58. The method of controlling the vacuum of a sealed vacuum tube, which consists in cooling said tube, and extracting gas therefrom automatically in response to change in degree of said vacuum.

59. The method of controlling the vacuum of a vacuum tube, which consists in cooling the tube, and extracting gas from or introducing gas into said tube automatically in response to change in degree of vacuum.

60. The method of operatingv a vacuum which consists in impressing electrical and hydrogen gas in contact with.

energy thereon, and during impression of energy vthereon controlling the temperature of said tube, and extracting gas therefrom automatically in responseto change in degreeof vacuum. v

61. The method of operating a vacuum tube, which consists in impressing electrical energy thereon, and during impression of energy thereon controlling the temperature of -said tube, and extractinggas therefrom and introducing gas into said tube automatically `in response to cha-nge in degree of vacuum. y g

l62. The method of operatingl a vacuum tube, which consists in impressing electrical energy thereon, and during impression of energyl thereon controlling the temperature of said tube, and extracting gas from and introducing gas into said tube automatically in response to change in degree of vacuum. 63. The method of operating a vacuum tube, which consists in impressing electrical energy thereon, and during impression of energy thereon controlling the temperature of said tube, and automatically introducing gas into'and extracting gas from said tube ,simultaneously at different rates.

64:. The combination with an X-ray tube having a vacuum raising' regulator, of automatic means responsive to fall of vacuum for controlling said regulator.

65. The combination with an X-ray tube haring a vacuum vraising regulator, of automatic means responsive to change in vdifference of potential between the terminals of said X-ray tube for controlling said regulator.

66. The combination with an X-ray tube, 'of a vacuum regulator comprising spark gap terminals, and automatic means responsive to changes in Vacuum for controlling thelength of said spark gap.

67. The combination with an X-ray tube, of a vacuum regulator therefor comprising an osmotic membrane, a terminal external to said tube separated from said membraneto form a spark gap, a second terminal separated from said terminal to form a second spark gap, and automatic means responsive to changes in vacuum for changing. the length of said second spark gap.

68. The combination With an X-ray tube, of a vacuum regulator comprising an osmotic membrane, a bulb on said tube inclosing said membrane, said membrane forming a Wall between the interior of said X-ray tube and said bulb, a transformer external to said bulb, and connections from the secondary of vsaid transformer into said bulb,

said membrane included in the secondary circuit of said transformer, said secondary circuit being in its entirety external to the vacuum of said X-ray tube.

69. The combination With an X-ray tube,

of a vacuum regulator comprising an os-J delivers energy for heating said membrane,

the current in the primary of said transformer automatically varying With changes of'diference of potential between the terminals of said X-ray tube.

70. The combination with an vX-raytube, of a vacuum regulator therefor comprising an osmotic membrane, a terminal external to said tube separated from said membrane to form 'a sparkv gap, and a transformer including said spark gap in its secondary lcircuit. v

71. The combination with an X-ray tube, of a step-up transformer for exciting the same, a--vacuum lregulator comprising an osmotic membrane, a transformer Whose secondary delivers energy for heating said membrane, and means for connecting the primary of said second transformer in a circuit inshunt with the primary of said lirst named transformer, whereby the current in the secondary circuit `of said second named transformer automatically varies With changes-of difference of potential between the terminals of said X-ray tube.

72. The combination With an X-ray tube, of a step-up transformer for exciting. the

same, a vacuum regulator comprising an,v

osmotic membrane, a terminal separatedi from said membrane to form a spark'gap, a

second transformer Whose secondary circuit includes said spark gap, the primary of said second transformer connected 1n a circuit in shunt Withl the primary of said first' With degrees of vacuum, an index associated with said scale, a vacuum. regulator, means for controlling said regulator, said means comprising means set by movement of said index.l

74. The combination with a vacuum tube, of vacuum lowering and raising regul-ators, a scale having markings corresponding With degrees of vacuum, an index associated With said scale, means for controlling said regulators, and means determining the operation of said' controlling means set With said index.

75. The combination with a vacuum tube, of vacuum loweringand raising regulators, a scale having markings corresponding With degrees of vacuum, an index associated With said scale, automatic means for controlling said regulators, and means determining the operation of said controlling means set With said index.

76. A regulator for the vacuum of a vacuum tube comprising an osmotic membrane,

va member thereon forming theA terminal of a spark gap, and another terminal external said spark gap.

Corrections in Letters Patent No. 1,143.32?.

77. A regulator for thefvacuum of a vacu-v k um tube comprising al tube'of osmotic `material, a protecting member on said tube forming the terminal of av spark gap, and a second member forming the other terminal of vsaid spark gap.

7 8.` The combination withv an X-ra tube,- of means for cooling the same, an

of vacuum of said tube for introducing into said tube an elemental gas. v

79. The combination with an X-ray tube, of means for cooling the same, and automatic means responsive to changein degree of vacuum of said tube for introducing into said tube hydrogen gas. Y

80. The combinationwith an X-ray tube, of means for cooling the same, automatic means responsive to change in degree of vacuum of said tube for introducing into said tube an elemental gas, and automatic means responsive to change in degree of Oiice.

[SEAL] r auto-l matic means responsive to change in degree vof means for cooling thesame,

Signed and sealed this 29th day of June, A. D., 1915.

81; The combination with an lvX-ray'gtube,

' of .means for l.cooling vthe same, Aautomatic lmeans res onslve to change infidegree of vacuum o said t'ube for lntroducin'g4 into sald -tube hydrogen gas,I and automatic means'responsiveito change in degree of vacuum of said tube for extracting gas vfrom said tube.V

82;v Thev combinationr with any X-ray tube,

automatically responding at different times and means,

to change in degree of vacuum of-saidtube for raising and @vering the vacuum" of said tube.

. In testimony W'hereofivvwe have hereuntol affixed our signatures in the presence of the twosbscribing Witnesses. I

HOMER CLYDE SNOOK. v vEDWIN. W. KELLY. Witnesses: r

ALICE S. MARSH, N ELLE FIELD.

It is hereby oertilied that in Letters Patent N o. 1,143,327, granted June 15, 1915, upon the application of Homer Clyde Snook, of Cynwyd, and Edwin W.'Kelly,of Philadelphia, Pennsylvania, for an limprovement: in Vacuum Regulation, errors appear in the printed specification requiring correction as follows: Page 2, line 95, after the comma, insert the words 07' n combination; page 5, line 107, for the word t arms read arcs; and that the said Letters Patent should be read with these oorrections therein that the same may conform to the record of the case in the Patent J. T. NEWTON,

Acting Commissioner of Patents.v 

